Conspiracy theorists claim second gunman was shooting from the fourth floor in Las Vegas

At least 58 people were killed and 527 injured by gunfire at an outdoor festival in Las Vegas Sunday. In the days after what has been labeled the nation’s deadliest mass shooting in modern history, stories have been shared online promoting a conspiracy theory that there was the second gunman.

The rumor, which was debunked by Snopes, has become so widespread it was addressed by Las Vegas police during a news conference.

"I want to emphasize we believe Paddock is solely responsible for this heinous act," LVMPD Asst. Sheriff Todd Fasulo told reporters Monday. "We are aware of the rumors outside of the media and also on social media that there was more than one assailant. We have no information or evidence to support that theory, or that rumor. We believe there was only one shooter and that was Stephen Paddock. We are doing a thorough investigation and only want to provide what is accurate to you. We will only give information that we have vetted and know to be true."

A large part of the "evidence" for this theory is a blurry Youtube video hosted by conspiracy sites like YourNewsWire and ZeroHedge.com that has been widely-shared by social media. The 35-second clip features a narrator who claims to have captured gunfire coming from the fourth floor of the Mandalay Bay hotel, where Paddock opened fire on thousands Sunday evening from a room on the 32nd floor.

Snopes, a website known for debunking stories of unknown or questionable origin, dissected the footage.

The site pointed out that according to the emergency radio traffic from that evening, which can be accessed through Broadcastify, officers did not initially know where the shots were coming from and received a number of reports from witnesses who believed there could've been more than one shooter at the time.

However, they eventually were able to pin Paddock's location to the 32nd floor after receiving witness accounts from guests who either stayed on or near that floor.

And, as Snopes found, the same could not be said for the fourth floor.